A variety of industries are subject to problems occurring with the growth of microorganisms. Such industries include, for example, the sporting equipment industry, the sporting apparel industry, the construction industry, medical healthcare institutions, the medical device industry, the lumber industry, and the textile industry. As such, reduction or elimination of microorganisms on surfaces is important in a broad variety of applications. One approach to interfere with the ability of microorganisms to survive on various materials is to modify the surface of those materials by attachment of antimicrobial agents.
Deciding how best to attach an antimicrobial agent to a material is guided, at least in part, by the planned end-use of the material. One important and useful consideration is that the antimicrobial activity be persistent. This may be achieved by permanently attaching the antimicrobial agent to the surface, so that it is unable to migrate or leach away from the modified material surface when the modified material is exposed to fluids. For example, for applications in which the modified material will come into contact with aqueous fluids, it is important that the antimicrobial agent is not rinsed away when the modified material comes into contact with aqueous fluids. For applications in which the modified material will come into contact with aqueous biological fluids, it is important that the antimicrobial agent is not rinsed away, or otherwise inactivated, when the modified material is exposed to aqueous biological fluids. For applications in which the modified material is to be used repeatedly, it is important that the antimicrobial agent is not washed or rinsed away when the modified material is washed or rinsed in fluids in between repeated uses.
One approach employs methods that attach silane-based quaternary ammonium compounds to particular substrates via a siloxane bond. For example, the AEGIS® product line includes products that utilize 3-(trimethoxysilyl)propyldimethyl octadecyl ammonium chloride. According to product literature, AEM 5700 includes 43% 3-trimethoxysilylpropyloctadecyl ammonium chloride in methanol, which can be used, e.g., to coat the surface of textiles. This is not a polymeric compound, although some interlinking of the applied silane may occur after application to the substrate. The methanol present in the commercial product AEM 5700 can be toxic, hazardous and therefore undesirable for some consumers. Another problem with the AEM liquid is the instability to pH change or temp/pressure changes. The product AEM 5700, upon removal of the methanol, will typically afford an oil or solid that is not readily soluble in water, and can degrade over time when exposed to ambient conditions.
The polymerized version of the AEM 5700 (Biosafe™) is a powder that is difficult to work with and leaves particulates behind upon dissolving in water. The Biosafe™, upon formulation into a sprayable liquid, includes an appreciable amount of undissolved solid particulates that should be removed (e.g., by filtering), or the sprayer can become clogged from the solid particulates. This can lead to costly and time-consuming steps in the production of liquid, sprayable commercial products manufactured from Biosafe™.
Consequently, there exists a need for antimicrobial compositions (e.g., ones that includes 3-(trimethoxysilyl)propyldimethyl octadecyl ammonium chloride), as well as methods of manufacturing the same in a convenient, reliable, and cost-effective manner.